Microstructural and densiometric analysis of extra oral bone block grafts for maxillary horizontal bone augmentation: a comparison between calvarial bone and iliac crest.

PURPOSE The main purpose of the present clinical study was to compare architectural metric parameters using micro-computed tomography (μ-CT) between sites grafted with blocks harvested from the intramembranous origin calvarium and endochondral origin iliac crest for horizontal bone augmentation in the maxilla. The second aim was to compare primary stability of implants placed in both types of block grafts. MATERIAL AND METHODS Nine consecutive healthy partially edentulous patients requiring extensive horizontal bone reconstruction in the maxilla were included in this study from July 2011 to March 2012. A total of 14 block grafts (seven each from the calvarium and iliac crest) were studied. After 6-7 months of the bone regeneration surgery, 43 implants were placed. Twenty-four implants (55.2%) were placed on calvaria (group 1) and 19 (44.8%) on iliac crest (group 2). All implants were clinically stable. A resonance frequency analysis (RFA) and μ-CT analysis were performed. Furthermore, two randomly biopsies were selected for histomorphometric analysis. RESULTS Micro-CT analyses evidenced completely different parametric values between intramembranous and endochondral extra oral bone block grafts, being the group 1 higher in density and in % of bone volume. However, these parametric values cannot be considered statistically different due to the sample size, excepting the trabecular thickness, which is statistically higher for group 1 (P = 0.06). CONCLUSION Calvarial bone blocks for horizontal maxillary augmentation provided a higher degree of bone volume and density than the iliac crest bone grafts. Nonetheless, both grafts provide implant with the same primary stability, as assessed by RFA.